Though theyre personal projects, Valve engineer Ben Krasnow has released videos showing off two devices hes made that allow video games to be controlled by the tongue and by how a player is sitting. Krasnow calls the latter device a posture-based controller, which allows users to move around a game world by sitting on it and shifting weight on their butt forward, backward, or side-to-side. This works better for virtual reality. This works better for virtual reality, Krasnow says.